Did you know? The Ottawa Valley is the valley of the Ottawa River, along the boundary between Eastern Ontario and the Outaouais, Quebec, Canada. The valley is the transition between the Saint Lawrence Lowlands and the Canadian Shield. Because of the surrounding shield, the valley is narrow at its western end, then becomes increasingly wide (mainly on the Ontario side of the river) as it progresses eastward. The underlying geophysical structure is the Ottawa-Bonnechere Graben.